How to Build a DIY Arduino Weather Station with Low Cost Sensors


Building your own weather station with an Arduino is a fun and educational project that allows you to get hands-on experience with electronics and programming. With just a few inexpensive components, I was able to build a weather station that measures temperature, humidity, barometric pressure, and rainfall.

In this guide, I will walk through the entire process of assembling the hardware, wiring up the sensors, and writing the code to display and log the weather data. I'll also provide tips on how to improve and expand the project by adding additional sensors.

Required Components

To build the basic weather station, you will need:

Optional Components

Assembling the Circuit

Here are the steps to assemble the circuit:

  1. Insert the Arduino into a breadboard.

  2. Connect the DHT22 sensor to 5V power, ground, and a data pin on the Arduino. I used a 10K ohm pull-up resistor on the data line.

  3. Connect the BMP280 pressure sensor to 3.3V power, ground, and the I2C pins on the Arduino.

  4. Connect the rain gauge to 5V power, ground, and a digital pin configured as an input.

  5. Connect the LCD screen to the appropriate pins on the Arduino. Follow the pinout for the specific LCD used.

  6. Connect buttons to control the LCD menu.

  7. Optional - Connect additional sensors like the real-time clock, anemometer, etc.

Carefully check all connections before powering on the Arduino!

Installing Required Libraries

To interface with the sensors, you'll need to install the following Arduino libraries:

To install a library, simply search for it in the Arduino IDE Library Manager.

Writing the Arduino Sketch

The Arduino sketch has the following key sections:

Declare Constants, Variables, and Objects

First, declare constants for the connected pins, variables to hold sensor data, and objects for the sensors and LCD.

const int DHTPIN = 2; // DHT22 data pin
const int RAINPIN = 3; // Rain gauge digital input

DHT dht(DHTPIN, DHTTYPE); // DHT22 object
BMP280 bmp280; // BMP280 object
LiquidCrystal lcd(RS, EN, D4, D5, D6, D7); //LCD object

float humidity;
float temperature;
float pressure;


In setup(), initialize the sensors, LCD, and any other components. Also initialize serial communication for debugging.

void setup() {




lcd.begin(16, 2);


Main Loop()

The loop() function runs continuously and reads the sensors, displays data on the LCD, and logs it to serial.

void loop() {

// Read DHT22
humidity = dht.readHumidity();
temperature = dht.readTemperature();

// Read BMP280
pressure = bmp280.readPressure();

// Print readings to LCD
lcd.print("Temp: ");

lcd.print("Humidity: ");

// Log to serial monitor

// Small delay


The full sketch brings together all the components into one program. Compile and upload it to the Arduino once complete.

Displaying Data on the LCD Screen

The LiquidCrystal library makes it easy to display sensor readings on the LCD. Some tips for the LCD menu:

With the LCD menu, you can cycle through all the weather data without needing to connect to a computer.

Logging Sensor Data

To log the sensor data over time, there are a couple options:

Logging allows you to collect long term weather records and analyze trends over time.

Enclosures and Mounting

For an outdoor weather station installation, the electronics need to be protected from the elements. Some options are:

Properly enclosing the weather station will allow the electronics to operate reliably for years.

Expanding the Project

Some ways to enhance the weather station:

By mixing and matching sensors, there are tons of possibilities for customizing your weather station!


Building a DIY Arduino weather station is an enjoyable and educational electronics project. With just a handful of inexpensive components, you can start collecting your own local weather data. The modular design also makes it easy to add new sensors over time.

While it requires some basic programming and electronics skills, the end result is a cool project that provides useful environmental data at home. Just remember to properly enclose the components for outdoor use.

I hope this guide gives you a starting point for creating your own Arduino weather monitoring system. Let me know if you have any other questions!